Problem description:
There are N heaps of coins on the table ordered in a row. In the i-th heap there are exactly ai coins.
Additionally, it is known that ai ≤ aj if i < j.
Alice and Bob play a game with these coins. At each move it is allowed to take any positive amount of coins from any heap, but the condition (ai ≤ aj if i < j) must remain satisfied. The player who takes the last coin, wins.
You should find who wins if no one makes a mistake and Bob gets to make the first move.
Input
The input consists of
• one line containing N (1 ≤ N ≤ 10^5) – the number of heaps
• one line containing N numbers a1, a2, ..., aN (1 ≤ ai ≤ 10^9) – the sizes of the heaps.
Output
If Bob wins output “Bob", otherwise output “Alice".
| Input | Output |
|---|---|
| 1 | Bob |
| 10 | - |
| ------ | ------ |
| 2 | Alice |
| 10 10 | - |
| ------ | ------ |
| 2 | Bob |
| 10 15 | - |
另有一组较大的测试数据,600个不同的数字
根据题意我提交的代码如下,虽然测试数据都是对的,但是并没有通过,希望大家可以帮忙看下哪里出了问题呢?
#include <iostream>
#include <algorithm>
using namespace std;
const int N = 100010;
/*
Lose First :a1 ^ a2 ^ a3 ^ ... ^an = 0
Win First:a1 ^ a2 ^ a3 ^ ... ^an ≠ 0
*/
int main()
{
int n;
cin >> n;
int res = 0;
while (n--)
{
int a;
cin >> a;
res ^= a;
}
if (res) puts("Bob");
else puts("Alice");
return 0;
}